class SessionEndTime:
    __earliestHour: int
    __latestHour: int

    @property
    def latestHour(self):
        return self.__latestHour

    @property
    def earliestHour(self):
        return self.__earliestHour

    def __init__(self, earliest_time, latest_time=None):
        self.__earliestHour = earliest_time
        if latest_time:
            self.__latestHour = latest_time
        else:
            self.__latestHour = self.__earliestHour

    '''
        最早时间和最晚时间 之间的差值
        可以取 (max_time - space_time ... max_time) 在方案表中的所有的值 
    '''
    @property
    def marginTime(self):
        return (self.latestHour - self.earliestHour) * 60
